Device for reading and cancelling thin film areolae of material having uniaxial, magnetic anisotropy and deposited on credit cards or the like

Device for reading and cancelling thin film areolae of material having uniaxial, magnetic anisotropy and deposited on credit cards or the like, comprising: (i) at least one head including a reading probe formed by a support member (14) carrying at least an assembly formed by an excitation winding (1) associated to a detection winding (2), said windings (1, 2) being wound in orthogonal relationship to each other around said support member (14); and at least a pair of cancellation electrodes (3, 4) assembled at the intersection area of said windings (1,2) and adapted to provide an electric arc therebetween and to be faced to the areolae (5) of the material to be examined and (ii) circuit means for producing the excitation current and for receiving the response signal representative of the characteristics of the material in the areola (5) under examination, and for effecting a comparison of the phase and the amplitude of said signal with reference signals as well as for detecting eventually the rotation by 180° of the magnetic moment vector by applying to said areola (5) orthogonal magnetic fields having intensities correlated to the characteristics of the material preselected for the areolae (5).